The question of the design of small locomotives for use on pioneer
lines has been always a difficult matter.
The needs of the railway contractor have called for such locomotives,
for which several systems of power have been tried. In many ways the
electric locomotive has distinct advantages over its rivals, steam and
compressed air, for these narrow gage lines. Reviewing these
advantages briefly, we see that the electrical equipment is more
economical to work, as one good stationary engine develops power much
more cheaply than several small locomotives. Again, the electric
locomotive can be more readily designed for narrow gages than steam or
compressed air locomotives.
[Illustration: FIG. 1--AN ELECTRIC LINE EQUIPPED ON THE KOPPEL
SYSTEM.]
[Illustration: FIG. 2.--THE SECTION WITH THE SUPPORT FOR THE OVERHEAD
LINE.]
A new system of equipment of such lines is now being introduced into
this country by Mr. Arthur Koppel, of 96 Leadenhall Street, E. C. The
keynote of this system is flexibility, the arrangements being such
that extensions or alterations can be readily effected. In fact, the
line is portable, and it is claimed also to be cheaper than the
ordinary construction. The overhead conductor is employed, as can be
seen from Fig. 1, which gives a general view of a locomotive and train
of skips on a line actually at work abroad. The supports for the wire
are not provided by separate posts and brackets in the usual way, but
by arched carriers attached to the sections of railway line, thereby
forming a portable section of the electric railway, as illustrated by
Fig. 2. The steel carrier or "arch" is fixed to one of the sleepers,
which is made of sufficient length for that purpose. On the straight
line these line supports are placed about 25 yards apart. In curves of
a small radius each section of tramway is provided with an arch, to
keep the line of the wire as nearly as possible parallel to the curve
of the line. Apart from these special extended sleepers with wire
carriers attached, the line is constructed in the ordinary mariner
with rails 14 lb. per yard and upward. As the electric locomotives are
lighter than steam locomotives, the weight of rail required is
somewhat less. The special trolley for erecting the wires along the
railway line is shown in Fig. 3. This consists of an ordinary four
wheeled platform wagon with ladder, and wire drum with tightening gear
and clamps or grips for anchoring the trolley to the line. The wire is
led over a sheave on top of the ladder and fixed to the picket post at
the beginning of the line. When erecting the wire the trolley is
pushed beyond the first carrier arch, clamped on to the rails, and the
wire is then tightened by means of the tightening gear. It is then
firmly fixed to the insulator on the carrier arch The tension in the
copper wire is taken up by a second portable ladder, which is also
provided with a tightening gear and can be clamped to the rails in the
same manner as the trolley, so that the trolley can then be pushed
behind the second carrier arch and the process previously described
repeated. By the tension in the wire the carrier arches acquire the
necessary stability, while without the procedure previously described
it would be impossible to use such light arches attached to the
sleepers. On permanent lines, the extreme ends of the wire are
attached to properly anchored picket posts. On portable lines, on the
other hand, the trolley with the wire drum is fixed to the rails at
the end of the line, as shown in Fig. 3, so as to enable the line to
be lengthened or shortened, as may be required, with ease.
[Illustration: FIG. 3.--THE STRAINING GEAR AND TERMINAL ANCHOR.]
Care is taken in insulating the drum and ladders so as to prevent
leakage from this erecting trolley to earth. The feeders from the
power house to the overhead wire and to the rails respectively are
erected on light iron posts, which have also been standardized by Mr.
Koppel. A specimen of these posts with an anchored stay is shown in
Fig. 4. All these details are arranged for convenience of the
contractor required to rapidly equip a line of railway, which can also
be removed as soon as the work has been done.
[Illustration: FIG. 4.--LIGHT POLE FOR CARRYING THE FEEDERS.]
[Illustration: FIG. 5.--THE KOPPEL LOCOMOTIVE.]
The locomotive used is varied in form with the gage of the line, but
we are particularly concerned with those for gages under 24 inches.
One form of such locomotive without a hood to protect the driver is
shown in Fig. 5. In this locomotive the gear is the same as that of
the next illustration, but it is securely boxed in a watertight iron
cover. The controlling gear is then placed vertically in front. Figs.
6 and 7 show the details of the electrical and mechanical parts of
this locomotive when fitted with a platform at either end, and with a
hood. The motor. M, is of the internal pole type, and is supported on
the underframe of the wagon. A double gear is used. The first is a
spur gearing, connecting the motor to a countershaft placed under the
motor. This gear reduces the speed of rotation to about 200
revolutions. The countershaft is then connected to the two axles of
the trolley by chain gearing. This gives the necessary flexibility
between the car body and the wheel required, as the springs give to
any inequality of the rails. In this gearing there is no change of
speed. The underframe is provided with spring axle boxes, and also
with spring buffers and drawbars. The speed of the motor can be
regulated within very wide limits by the regulator, R. An effective
hand brake is also provided.
[Illustration: FIG. 6.--END ELEVATION OF LOCOMOTIVE.]
[Illustration: FIG. 7.--DETAILED ELEVATION OF A KOPPEL LOCOMOTIVE WITH
A DOUBLE PLATFORM AND HOOD.]
For gages of 20 inches and upward the motors can be mounted on springs
and attached to the running axles inside of the wagon underframe. This
construction is particularly recommended by Mr. Koppel where, in order
to mount heavy gradients, the dead load of the motor car must be
assisted by the paying load to produce the necessary adhesion. In such
cases several motor wagons would be used in the same train. As regards
the working voltage, this can be varied to suit special requirements,
but the locomotive we illustrate was designed for 110 volts. At this
pressure its possible working speed was at least eight miles per hour.
The supply of power is also a matter not referred to particularly, as
in many cases a lighting plant is used by the contractors, which could
also be employed to provide the necessary energy for the electric
railway. The good work done by small electric locomotives in the
excavation work for the Waterloo and City Railway[1] will convince our
large contractors of the valuable service which electricity can render
both above and below ground.--The Electrical Engineer.
[Footnote 1: Electrical Engineer, vol. xvi., p. 499.]
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A connection between Servian and Roumanian railways is to be
established by bridging the Danube. It is reported proposals have
already been made to the governments interested, by the Union Bridge
Company, also by British and French constructors.--Uhland's
Wochenschrift.
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